Single-epoch Positioning Method in Network RTK with BDS Triple-frequency Widelane Combinations

Abstract

Using the advantage that triple-frequency extra-widelane or widelane ambiguities have much longer wavelength and thus are easy to be fixed,a new network RTK(real-time kinematic)single-epoch positioning method based on BDS widelane combinations is proposed.The data processing center uses reference stations to calculate and broadcast the real-time virtual observations including double difference(DD)tropospheric and ionospheric delay correction.Then using single-satellite-pair and single-epoch mode,two extra-widelane or widelane ambiguities are resolved reliably by carrier-pseudo combination and TCAR(three-carrier ambiguity resolution)method at the rover station.Finally,the ambiguity-fixed widelane observations with the minimum observation noise and the broadcast atmospheric correction are used together to calculate the real-time kinematic positioning results.Experimental results show that the correct rates of single-epoch widelane ambiguity resolution at rover stations are larger than 99.9%.The statistical positioning error in plane is 3-4cm,and the error in up direction is about 5cm.